Chemical composition and biological activities of the essential oils of two endemic Nepeta species

The chemical composition, antioxidant activity and several enzyme inhibitions of the essential oils of two endemic Nepeta species, N. nuda subsp. glandulifera and N. cadmea were investigated for the first time. The major compounds of N. nuda subsp. glandulifera essential oil were geijerene (61.02%) and neointermedeol (6.07%). On contrary, essential oil of N. cadmea contained 70.94% of 4aβ,7α,7aβ-nepetalactone. The oil of N. nuda subsp. glandulifera revealed better activity than the oil of N. cadmea against both reducing metal ions and radicals. Moreover, both oils have relatively weak but still noticeable activity against acetylcholinesterase and butyrylcholinesterase; weak activity against α-glucosidase, but quite high activity against α-amylase. On the other hand, both essential oils showed significant activity against tyrosinase. Presented results suggest that these two endemic species have strong potential to be used in food and pharmacological industries, and therefore they should to be investigated further. © 2018 Elsevier B.V